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Date: Tue, 12 Feb 2008 21:53:30 +0100
From: Ruediger Pluem <rpluem@apache.org>
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To: dev@httpd.apache.org
Subject: Re: idempotent http methods (svn commit: r617822)
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On 02/02/2008 09:14 PM, Ruediger Pluem wrote:
> 
> On 02/02/2008 07:08 PM, Nick Kew wrote:

>> Suggested solution: an enum, with a third value for an idempotent
>> method with arguments.  The caller then determines how to use it.
> 
> So you think of something like this (ok, no enum, but similar):
> 
> #define METHOD_NON_IDEMPOTENT       0
> #define METHOD_IDEMPOTENT           1
> #define METHOD_IDEMPOTENT_WITH_ARGS 2
> 
> static int is_idempotent(request_rec *r)
> {
>     /*
>      * RFC2616 (9.1.2): GET, HEAD, PUT, DELETE, OPTIONS, TRACE are considered
>      * idempotent. Hint: HEAD requests use M_GET as method number as well.
>      */
>     switch (r->method_number) {
>         case M_GET:
>         case M_DELETE:
>         case M_PUT:
>         case M_OPTIONS:
>         case M_TRACE:
>             /*
>              * If the request has arguments it might have side-effects and thus
>              * it might be undesirable to resent it to a backend again·
>              * automatically.
>              */
>             if (r->args) {
>                 return METHOD_IDEMPOTENT_WITH_ARGS;
>             }
>             return METHOD_IDEMPOTENT;
>         /* Everything else is not considered idempotent. */
>         default:
>             return METHOD_NON_IDEMPOTENT;
>     }
> }

Ok, committed as r627097.

> 
>> That's in response to your post to dev@.  OTTOMH it seems to me
>> to work as a core function.  How many existing handlers apply
>> an equivalent test?
>>
> 
> I know of none currently, but I assume that at least in mod_proxy(_http) the
> need for this test will rise, once we try to finally solve the race problem in
> mod_proxy_http when it sends a request over a connection that is closed just
> at this moment.

Ping, WDYT now? core or proxy_util?

Regards

Rüdiger